'γ 射线-BaF2-纳米TiO2'辐照催化体系降解金橙 Ⅱ

摘要

In order to realize the proper treatment of wastewater containing azo dyes,a silica-base supported BaF2-nano-TiO2 composite (hereinafter called the composite) was prepared by a three-step synthetic procedure and utilized for the decolorization and degradation of orange Ⅱ in aqueous solution. It was found that the irradiation time and solution pH value was important parameter that ensured the degradation effect of γ-rays at low dose. The optimal doping ratio of BaF2 to nano-TiO2 was determined to be 1:1 (mBaF2:mTiO2). Furthermore, it was found that a highly reductive atmosphere (N2) favored the formation of hydroxyl radicals (·OH), which were responsible for the efficient degradation and mineralization of orange Ⅱ. The decolorization rate of the orange Ⅱ, Reactive black 5 and Reactive blue 222 dyes solution by the radiocatalysis system was 96.8%, 95.3% and 99.9%, respectively; and total organic carbon (TOC) removal rate of the orange Ⅱ, Reactive black 5 and Reactive blue 222 dyes solution achieved 92.5%, 40.2% and 98.6%, respectively. Thus, it was shown that the composite could be applied to the treatment of wastewater containing azo dye mixtures. The results of this study extend the technical applications of the TiO2 photocatalytic oxidation technology.%为实现含偶氮染料废水妥善处理,采用三步式制备工艺合成硅基负载"BaF2-纳米TiO2"复合材料,实现了含金橙 Ⅱ 染料废水的脱色与降解矿化.研究发现,辐照时间和溶液pH值为确保低剂量辐照催化降解效果的重要条件参数,BaF2与TiO2存在最适掺杂比例(mBaF2:mTiO2=1:1),N2气氛有利于生成更多的羟基自由基降解金橙Ⅱ."γ射线-BaF2-纳米TiO2"辐照催化体系对金橙Ⅱ、活性黑5和活性蓝222的脱色率可分别达到96.8%、95.3%和99.9%,TOC去除率分别为92.5%、40.2%和98.6%.研究结果说明,该复合材料可应用于含混合偶氮染料分子的印染废水处理,扩展了TiO2光催化技术的环境应用范围.